Providing precision control over the time delay, amplitude and phase delay of a radio frequency (RF) signal is fundamental to many applications that require precision and programmable RF signal conditioning. These applications include wideband array beam formation and diversity aperture combining.
In conventional true time delay devices, a control of time delays and phase is not independent from each other. Changing the time delay affects the phase delay of the carrier of the signal. The coupling of time delay and phase delay creates complexity at the system level, and is not desired for applications that require advanced signal conditioning techniques.
In conventional beamforming networks, time delays are located in a corporate feed structure. Prior art generally uses a two dimensional corporate tree feeding network, which can be physically larger than the present invention because of the two dimensional topology. The corporate feed structure is costly to implement, especially when feeding a large phase array with thousands of radiating elements.
Examples of the conventional beam forming networks include U.S. Pat. Nos. 6,894,654 and 7,271,767, hereby incorporated herein by reference in their entirety.
It would be desirable to develop a beamforming network that is streamlined over a conventional network and minimizes the required aggregate time delay, wherein the beamforming network minimizes overall package size and associated cost.